Method of thermochemically severing tubular metal members



June 12, 1951 .1. L. ANDERSON 2,556,786

METHOD OF THERMOCHEMICALLY SEVERING TUBULAR METAL MEMBERS Filed May 24,1947 ATTORNEY J Patented June 12, 1951 METHOD OF THERMOCHEMICALLY SEVER-ING TUBULAR METAL MEHBERS James L. Anderson, Closter, N. J., assignor toAir Reduction Company, Incorporated, a corporation of New YorkApplication May 24, 1947, Serial No. 750,210

4 Claims.

This invention relates to a method of thermochemically severing tubularmetal members.

There are times when it is desirable to thermochemically sever tubularmetal stock very rapidly even though this may result in a rough and poorquality out, and it is the principal object of the invention to providea method by which this can be accomplished.

By the use of the method to be herein described rough severing of tubesof practically any diameter can be accomplished thermo-chemically in amatter of seconds.

The improved method, and apparatus suitable for use in carrying it out,are illustrated in the accompanying drawing, in which:

Figure 1 is a side elevation, partly in section, of an annular torch tipwhich is adapted to sever tubes in accordance with the improved method;

Fig. 2 is a horizontal section taken approximately on the line 2'2 ofFig. 1; and

Fig. 3 is a plan view of a section of tubing thathas been severed by themethod of the invention showing the nature of the cut that is produced.

According to the invention a metal tube is thermo-chemically severedwith great rapidity by projecting against the tube, while the metal atthe cutting Zone is at kindling temperature, a number of cutting-oxygenjets arranged in a circular series extending entirely around the tubeand which are directed tangentially toward the tube. The cutting-oxygenjets are preferably directed tangentially with respect to the innersurface of the tube and are so spaced circumferentially of the tube thateach jet gouges a cut through the wall of the tube which extends a shortdistance circumferentially of the tube to the next adjacent jet where itjoins and forms a continuation of the cut made by that jet. Thus, in thetime that it takes a single jet to gouge through the wall of the tube,the tube is completely severed around its entire circumference by thejoint action of all of the oxygen jets. The heating of the tube tokindling temperature may be performed in a furnace or the like beforethe tube is positioned in the cutting apparatus, but preferably themetal of the tube is heated to kindling temperature by preheating flamesdirected against the tube at the cutting zone by the same apparatus thatdirects the cuttingoxygen jets against the tube.

The method can be satisfactorily carried out by the use of an oxy-fuelgas cutting torch having an annular tip structure of the kind shown inthe accompanying drawing. In Figs. 1 and 2 the annular tip structure isshown at I0. It is 2 adapted to receive and completely surround a metaltube shown at W in Fig. 1. The annular tip structure may be made up of anumber of segmental sections suitably fastened together, but preferablyit is a unitary annular ring of the kind illustrated.

As best shown in Fig. 1, the annular tip structure has a number ofcutting-oxygen jet passages i 1 arranged in a circular series thatextends completely around the tube W. The jet passages H aretangentially disposed with respect to the tube so as to projectcutting-oxygen jets tangentially toward the tube, several of suchcutting-oxygen jets being represented at [2. The cutting-oxygen isdistributed to the jet passages I I by one or more cireumferentiallyextending distributing chambers formed in the annular tip structure.Preferably two or more such distributing chambers are used dependingupon the diameter of the work-piece involved; a larger diameterrequiring a greater number of distributing chambers to provide evendistribution over a greater circumference. Here shown there are two suchchambers, semi-circular in shape and symmetrically arranged atdiametrically opposite sides of the annular tip structure, one of suchdistributing chambers shown at I3, serving to distribute oxygen toone-half of the total number of jet passages H and the seconddistributing chamber M serving to distribute cutting-oxygen to theremaining half of them. Cutting-oxygen is supplied to the distributingchamber 13 through an inlet pipe l5 and to the distributing chamber l4through a second inlet pipe I 6. As best shown in Fig. 2, thedistributing chamber l3 may be conveniently formed in the annular tip itby providing in one of its side faces a recess ii that extendscircumferentially part way around the annular tip and is closed by aplate 88. The distributing chamber i l may be similarly formed in theannular tip by a recess [9 closed by a plate 29. The plates l8 and 20may be soldered or otherwise fastened to the annular tip. The tangentialjet passages l I lead from the distributing chambers thus formed to theinner face ll of the annular tip. The inner face of the annular tip ispreferably notched at the inner terminus of each of the jet passages II,as shown at 22, so that the discharge orifice of each of the jetpassages will lie in a surface 23 (Fig. 1) that is sub stantially normalto the axis of the jet passage.

'The annular tip structure is also preferably provided with a number ofpreheat jet passages 24 arranged in a circular series extending entirelyaround the tube W. These passages may be normal to the surface of thetube and may be fed with a combustible gas mixture such as a mixture ofoxygen and acetylene, or other fuel-gas, by means of one or moredistributing chambers in the annular tip structure. There are preferablytwo or more such distributing chambers also depending upon thecircumference over which the jets must be uniformly discharged. In thestructure illustrated two such chambers are adequate, one being shown at25 in Fig. 1 for distributing the combustible gas mixture to one-half ofthe total number of preheat jet passages and the other shown at 23 fordistibuting the combustible gas mixture to the other half of them. Thetwo distributing chambers 25 and 26 may be conveniently formed in theannular tip by providing an annular recess 2'! in a side face of the tip(Fig. 2), closing it by a plate 28, and dividing the annular recess intotwo chambers by means of two plugs 29 and 30 (Fig. l). The preheat jetpassages 2 lead from the two distributing chambers thus formed to theinner face 2! of the annular tip. The combustible gas mixture issupplied to the distributing chamber 25 through an inlet pipe 3i, and tothe distributing chamber 26 through an inlet pipe 32.

If desired, the torch tip may be cooled by cooling water delivered tothe tip through a tube 33 and circulated around the tip in a passage 3dand then discharged through a tube 35. A plug 36 (Fig. 1) closes off thepassage 3 3 between the inlet and discharge tubes 33 and 35, thuspreventing a short-circuited flow of the cooling water directly from theinlet tube to the discharge tube instead of through the major portion ofthe cooling passage. The cooling passage 34 may be formed similarly tothe gas distributing chambers, namely, by providing a circularlyextending recess in one side face of the torch tip closed by a plate Bl(Fig. 2).

In using the apparatus to carry out the method, the tube W is insertedin the central opening of the annular tip and the tube and tip arerelatively supported in any suitable way so that the outer surface ofthe tube is uniformly spaced from the inner face of the tip around theentire circumference of the tube. The metal of the tube is then broughtto kindling temperature by the preheating fiames, several of which arerepresented at 38 in Fig. 1, after which the supply of cuttingoxygen isturned on. ihe cutting-oxygen jets l2, being directed tangentially withrespect to the inner surface of the tube W, will each gouge a cut in thewall of the tube which extends a short distance circumferentially of thetube. When the oxygen jets are spaced close enough togethercircumferentially of the tube the separate cuts made by the oxygen jetswill join to produce one continuous cut extending completely around thetube and of sufiicient depth at all points to sever the tube. Theparticular annular torch tip shown in the drawing is not adjustable andis adapted for cutting tubes having the relative diameter and relativewall thickness shown in Fig. 1, although tubes that are slightly largeror slightly smaller in diameter and thickness can be cut by the sametorch tip. If the tube is too small in diameter the tangential angle ofthe cuttingoxygen jets will not be steep enough to cut the wall of thetube. If the tube is too large the cutting-oxygen jets may tend topierce holes in the wall of the tube instead of gougingcircumferentially extending cuts in it, or the individual cuts may notjoin to produce a circumferentially continuous cut. It is probably morefeasible to use for each size tube a non-adjustable torch tip designedespecially for severing that size tube than to use a single adjustableone for severing tubes which vary in diameter and thickness over a widerange since such a, tip would have to have some provision for varyingthe number and tangential angle of the cutting-oxygen jets. By incliningthe cutting-oxygen jet passages more steeply than shown in Fig. 1 theannular tip illustrated in the drawing could be used for severing tubeswhose size relative to the annular tip is smaller than depicted in Fig.1.

The molten slag produced by the cutting operation is blown from the outby the force of the cutting-oxygen jets. To prevent the slag from beingblown by the oxygen jets onto opposing surfaces of the annular torch tipand clogging the discharge orifices in such surfaces, the cuttingoxygenjet passages H are preferably inclined with respect to the longitudinalaxis of the tip and the tube as shown in Fig. 2 so that the oxygen jetsblow the molten slag outside of the region enclosed by the inner face ofthe torch tip. The preheat passages 24 are preferably inclined in asimilar manner so that the preheating flames fed by them will impinge onsubstantially the same area of the tube that the cutting-oxygen jetsimpinge on. When the torch tip has cuttingoxygen jet passages inclinedas just described, and tangentially disposed as shown in Fig. 1, the cutmade in the tube W will appear somewhat as shown in Fig. 8 at C. Whilethe inclination of the cutting-oxygen jets relative to the longitudinalaXis of the tube tends to cause the end portion of each cut to beslightly offset relative to the beginning of the next cut, neverthelessthe cuts will join and be continuous if they are wide enough or if thereis a flare in the width of the end portion of each cut as depicted inFig. 3. It will be seen from this figure that the cut is a rough one butin certain severing operations this is immaterial, the importantconsideration being rapid severance of the tube. The present inventionmakes it possible to sever a tube in a few seconds regardless of thediameter of the tube, when a torch tip is employed that is designed foruse with the size tube being severed.

It will be understood that in the foregoing description, and in theaccompanying claims, the characterization of the cutting-oxygen jets asbeing directed tangentially toward the tube does not mean that the jetsare necessarily truly tangent to the outer or inner surface of the tube.While the cutting-oxygen jets are preferably tangent to the innersurface of the tube, or nearly so, so that they will gouge grooves inthe tube wall and effect substantially complete severance of the tubewhen the proper oxygen pressure is employed, they could be at a steeperangle if desired so long as they will not pierce holes in the tube wallat the oxygen pressure employed instead of grooving the tube wall.

I claim:

1. ihe method of therrno-chernically severing cylindrical metal tubeswhich comprises heating the metal at the cutting zone to kindlingtemperature and directing against the tube oxygen jets arranged in aseries around the tube in fixed relaticn to the tube and directedtangentially toward the tube, the jets being close enough togethercircumferentially of the tube and directed at such an angle with respectto the tube that without relative movement between the tube and theoxygen jets a circumferentially continuous cut is produced having adepth at all points sufficient to cause substantially complete severanceof the tube.

2. The method of thermo-chemically severing cylindrical metal tubeswhich comprises heating the metal at the cutting zone to kindlingtemperature and directing against the tube oxygen jets arranged in aseries around the tube in fixed relation to the tube and directedtangentially toward the tube and also at an inclination with respect tothe longitudinal axis of the tube, the jets being close enough togethercircumferentially of the tube and directed at such an angle with respectto the tube that without relative movement between the tube and theoxygen jets a circumferentially continuous cut is produced having adepth at all points sufficient to cause substantially complete severanceof the tube.

3. The method of thermo-chemically severing cylindrical metal tubeswhich comprises heating the metal at the cutting zone to kindlingtemperature and directing against the tube oxygen jets arranged in aseries around the tube in fixed relation to the tube and directedtangentially with respect to the inner surface of the tube, the jetsbeing close enough together circumferentially of the tube to producewithout relative movement between the tube and the oxygen jets acircumferentially continuous cut having a depth at all points sufficientto cause substantially complete severance of the tube.

4. The method of thermo-chemically severing cylindrical metal tubeswhich comprises heating the metal at the cutting zone to kindlingtemperature and directing against the tube oxygen jets 6 arranged in aseries around the tube in fixed relation to the tube and directedtangentially with respect to the inner surface of the tube and also ataninclination with respect to the longitudinal axis of the tube, the jetsbeing close enough together circumferentially of the tube to producewithout relative movement between the tube and the oxygen jets acircumferentially continuous cut having a depth at all points sufiicientto cause substantially complete severance of the tube.

JAMES L. ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,352,381 Reynolds Sept. 7, 19201,701,388 Remane Feb. 5, 1929 1,723,107 Wildeboer Aug. 6, 1929 1,775,311Halle Sept. 9, 1930 1,888,385 Jenkins Nov. 22, 1932 2,054,375 HalleSept. 15, 1936 2,221,788 Doyle Nov. 19, 1940 2,252,320 Hughey Aug. 12,1941 2,266,208 Jones Dec. 16, 1941 2,284,711 Anderson June 2, 19422,347,245 Anderson Apr. 25, 1944 2,417,412 Herbst Mar. 18, 1947 FOREIGNPATENTS Number Country Date 701,786 France Mar. 23, 1931

